The present invention relates to a damper mechanism provided on an opening-and-closing member or the like, for example, a glove box of an automobile, for absorbing impact when the opening-and-closing member is opened and closed, and a damper device for damping a movement of a movable body attached to a fixed body so that the movable body is drawn out or opened up.
In a conventional damper mechanism disclosed in, for example, Japanese Patent Publication (Kokai) No. 05-76894 as shown in FIG. 24(A), a piston 104′ is disposed in a cylinder 100′ and slides along an inner wall surface of the cylinder 100′ with an O-ring 102′ in between. An annular cap 106′ is provided on a front end of the cylinder 100′ and a guide surface 106A′ having a curved surface is formed on an inner surface side of the cap 106′. A first space part 108′ is provided between the cap 106′ and the piston 104′, and a compression spring 110′ is disposed in the first space part 108′.
Furthermore, a dividing wall 114′ having an air flow-through hole 112′ formed in the center thereof is formed on a back end side of the cylinder 100′, and a second space part 116′ is provided by means of the piston 104′ and the dividing wall 114′. A third space part 118′ is provided on a back end part of the cylinder 100′ between the dividing wall 114′. A valve 120′ is provided inside the third space part 118′ for closing the flow-through hole 112′. An orifice 122′ is formed at the center of the valve 120′, and the second space part 116′ and the third space part 118′ are communicating via the flow-through hole 112′ and the orifice 122′.
One end part of a cord member 124′ is attached to a side of the first space part 108′ of the piston 104′. As shown in FIG. 24(B), the other end part of the cord member 124′ is linked to a linking member 128′ of the glove box 126′ through the guide surface 106A′.
With the structure described above, when a push-button type or pull-handle type lock (not shown) is released in a state that the glove box 126′ is in the closed state, a rotational moment is applied to the glove box 126′ in the opening direction by its own weight. The glove box 126′ pulls the cord member 124′ and moves the piston 104′ in the opening direction (arrow direction) against a force of the compression spring 110′. Accordingly, the cord member 124′ is drawn out through the guide surface 106A′, and the glove box 126′ begins to open.
At this time, while the glove box 126′ receives damping action through fluid resistance of the orifice 122′, the glove box 126′ is opened in the opening direction, and the piston 104′ is drawn out by the cord member 124′ and moves up to the open position.
In the closing operation of the glove box 126′, the piston 104′ moves in a direction opposite to the opening direction by the force of the compression spring 110′ and the valve 120′ is opened, so that air passes through the flow-through hole 112′. Accordingly, in a state that the load on the piston 104′ is reduced, the cord member 124′ is pulled into the cylinder 100′, and the glove box 126′ is locked at the closed position of the glove box 126′.
In the conventional damper mechanism disclosed in Japanese Patent Publication (Kokai) No. 05-76894, the linking member 128′ is located at the center part of the glove box 126′. Accordingly, there is a difference between a moving path of a free end of the glove box 126′ and that of the linking member 128′. That is, the moving path of the linking member 128′ is smaller than that of the glove box 126′. Accordingly, there is an idle distance before the damper begins to take effect, thereby making it difficult to follow a sudden movement.
Further, in a case of an air damper, a dimension of the cylinder 100′ changes according to a temperature change, thereby causing a variation in the resistance or losing the damping due to leakage of air. In a case of an oil damper, a viscosity of oil increases in a low-temperature region, thereby increasing a torque and making it difficult to open the glove box 126′ by its own weight.
Also, U.S. Pat. No. 5,690,194 and U.S. Pat. No. 5,839,548 have disclosed damper devices for damping only when a movable body moves in one direction. Each of the damper devices includes a rack moving together with the movable body and a pinion engaging the rack. A viscous fluid damps the pinion when the pinion rotates.
In the damper devices disclosed in U.S. Pat. No. 5,690,194 and U.S. Pat. No. 5,839,548, when the movable body moves in the opposite direction, the engagement between the rack and the pinion is released. Accordingly, it is difficult to securely engage the pinion with the rack again when the movable body moves again in the one direction, thereby requiring a special mechanism in order to assure stable operation.
In view of the problems described above, an object of the present invention is to provide a one-way type damper mechanism in which an idle time before the damper takes effect is short, and the damper effect is obtained regardless of a temperature.
Another object of the present invention is to provide a damper mechanism that applies the damping only when a movable body moves in one direction. In the damper mechanism, a rack portion of a rack part moves with a movable body, and always engages a pinion portion of a damping part during the movement of the movable body, so that the damping is securely applied only when the movable body moves in the one direction.
Further objects and advantages of the invention will be apparent from the following description of the invention.